1. Field of the Invention
The present invention relates to the art of stereoscopic motion picture display, and more specifically to coordinating two projectors for stereoscopic motion picture projection wherein illumination and temporal binocular symmetrical constraints are met.
2. Description of the Related Art
Stereoscopic displays in general—and stereoscopic motion picture systems in particular—must adhere to an important design constraint called binocular symmetries, first articulated by Lipton, in Foundations of the Stereoscopic Cinema, Van Nostrand Reinhold, New York, 1982. Binocular symmetries are an optical symmetrical or congruence principle, in which the left and right image fields must be carefully matched to within specifiable tolerances in order to insure that the stereoscopic image provides a pleasing image.
If this symmetrical constraint is not met, the result for the observer is what people sometimes call “eyestrain,” which describes the unpleasant sensation arising when viewing stereoscopic images. Some people will report the unpleasant sensation, as mentioned, as eyestrain; others will call it fatigue or a headache. Whatever it is called, since such asymmetries do not occur in the visual world, there is no generally accepted nomenclature to describe the resultant sensations. Therefore, people refer to the discomfort encountered by whatever name they find to be convenient or possible to the part of the body to which the discomfort is referred. The binocular symmetries are classified into three major categories: illumination, temporal, and geometrical.
Stereoscopic moving images are transmitted using projection systems, including but not limited to the ZScreen® design available from StereoGraphics Corporation. When binocular symmetries (illumination, temporal, and/or geometrical) occur using the ZScreen or any type of digital projection system, the aforementioned discomfort to the viewer can result.
It is beneficial to provide a system addressing and overcoming the binocular symmetry problems present in previously known projection designs, and to provide a stereoscopic projection arrangement or design having improved functionality over devices exhibiting those negative aspects described herein.